West Africa

Sept. 1, 2000
ExxonMobil is getting ready for a comprehensive review of OPL 209 in deepwater Niger Delta, which has given the company a large gas find (Bosi-1) and a huge oil field (Erha).

ExxonMobil planning large 3D program

ExxonMobil is getting ready for a comprehensive review of OPL 209 in deepwater Niger Delta, which has given the company a large gas find (Bosi-1) and a huge oil field (Erha). The company plans to acquire 2, 250 sq km of 3D seismic data, a complete blanket coverage of the 2,200 sq km lease.

The implication is that some of the 3D data already acquired will be run over again. ExxonMobil leads the charge for oil in Nigeria's deepwater, holding interests in Shell's 800 million bbl Bonga field, 47% of Conoco's OPL 220 holding, as well as 30% in TotalFinaElf's operated OPL 222 license. The pending 3D survey, which will commence in January 2001, will be carried out by CGG's Alize S/V.

Unitization getting more attention

Three deepwater fields offshore the Niger Delta are among more than 50 straddled fields, which will benefit from improved guidelines for unitization in Nigeria, the subject of a workshop held in early August. Experts on reservoir management, who assembled at a workshop at the Abuja Hilton, discussed the essence of joint reservoir development, review of unitization procedures, and case histories on straddled fields off Nigeria.

The workshop was one of several phases in the proposal to have a comprehensive legislation on the subject of unitization in the Nigerian oil industry. A straddled field is an oil pool which crosses concession boundaries.

Unitization is the framework under which such fields can be jointly developed. For all the 42 years of oil production in Nigeria, such pools have been developed separately by operators on either side of the concession boundary. The result has been unneccessary competition on either side and inefficient drainage of reservoirs. The Nigerian government wants to encourage unitization of all fields found to be straddled, for the reason that "it ensures maximum ultimate recovery."

Deepwater fields that are candidates for unitization include the 1-billion bbl Agbami, the 250-million bbl Chota, and the Nnwa gas field. Agbami straddles Famfa/Texaco's OPL216 and Statoil/Texaco's OPL 217. In fact, Statoil just completed drilling their side of the pool. Chota extends from Conoco's OPL 220 into Shell's OPL 219, as well as South Atlantic's OPL 246. The Nnwa field is jointly encountered by Shell (OPL 219) and Statoil (OPL 218).

Two discovery wells drilled in 6,000 ft depths

Two record water depth wells were drilled recently - one off Nigeria and one off the Congo.

  • Three weeks after TotalFinaElf reported that Akpo 1 flowed 9,000 b/d of light oil during a drilling stem test of two zones in Akpo (OPL 246) in 1,375 meters of water, Texaco released partial results of Ikifa-1, 20 km to the west and confirmed rumors of a huge discovery. Texaco said that Ikifa-1 on OPL 216 off Nigeria channeled 240 ft net oil in multiple zones between 11,500-15,750 ft, adding that the well is the deepest in the deepwater Niger Delta, both in terms of water depth (6,066 ft) and total depth (17,500 ft).
  • TotalFinaElf set a new water depth record for the Congo with the Andromende Marine discovery well. The well was drilled in 1,893 meters water depth on the Mer Tres Profonde Sud concesssion. The well tested at 7,000 b/d of oil. At the same time, the Kombi and Likala fields began producing and will increase the country's oil output by two million tons.

Independents escalating East African search

There is a buzz in oilfield activity in East Africa. Star Petroleum has signed an agreement with the Kenyan government for three leases covering 34,893 sq km offshore Lemu; Western Geophysical has begun a 2D seismic survey covering 4,100 km in Pemba Basin, located in the northeast offshore Tanzania; Heritage Oil and Gas announced that test drilling for oil in Uganda would begin before the end of the year; Hunt Oil has scheduled the spud of Majunga North West well in the Majunga Basin, off Madagascar, for October.

These activities represent an unusual surge in a region that is known more for low activity. Some observers even say that the heightened activity is merely a passing phase of an exploration cycle. But the companies involved appear to be very serious.

In Kenya, Star Petroleum is committed to seismic interpretation and acquisition of a 500-km 2D seismic survey in the first two years and one well on each lease every two years of the four year contract.

Heritage Oil went to Uganda only after positive results were reported from geological surveys in the Lake Albert area. The seismic shoot in Pemba Basin in Tanzania is the second phase of a non-exclusive survey of the basin, which began with 7,100 km of data acquired in 1999 and will be used for the planned announcement of the Tanzanian First Offshore Licensing Round.

Ceibe FPSO to host high flow rates

Triton Energy and Bergesen DY Offshore AS are preparing the (2 million bbl) Sendje Berge floating production, storage, and offloading (FPSO) vessel for Triton's initial development of the Ceibe Field off the Republic of Equatorial Guinea.

Triton budgeted $90 million for the development, excluding the FPSO, which will likely be leased. The vessel will provide an initial producing capacity of 60,000 b/d, expandable over the longer term to 240,000 b/d. Triton's two Ceiba discovery wells on Block F and Block G are in 700 meters water depth.

Triton began exploration on the blocks in late 1997, acquiring 2,500 km of 2D seismic as well as magnetic and gravity data. The Cieba-1 explor-atory well was spudded in Block G in late August. This encountered a 225-meter gross oil column with net pay of 95 meters in four zones, with one 50-meter interval testing 12,400 b/d of 30 degrees API (constrined flow). Triton estimated a flow rate of 20,000 b/d following completion.

Appraisal well Ceiba-2 was drilled was drilled one mile to the southwest and 194 ft downdip of Ceiba-1 and ecountered 300 ft net oil pay in a single continuous column. It also confirmed the oil-water contact found in the first well, and demonstrated lateral reservoir continuity and connectivity. Total depth was around 8,740 ft. A similar production rate to that of Ceiba-1 is expected, following completion.


SCORE higher than 1999

Global Marine's industry SCORE shows West Africa's July score of 35.5 decreased 1.3% from June 2000. This region's score is 20.5% above its level in July of last year, but 8.0% below the level of five years ago.

South Africa potential

Petroleum Agency SA and Global Energy Holdings have entered into a technical cooperation agreement to study oil and gas potential in block 3B and block 4B off the west coast of South Africa.

Sierra Leone survey

TGS-NOPEC Geophysical commenced a non-exclusive 2D seismic survey off Sierra Leone. The 2,500-km program is a joint effort between TGS-NOPEC and the Min-istry of Mineral Resources of Sierra Leone in preparation for an upcoming bid round in 2001.